1) Field of the Invention
The present invention relates to a recording/reproduction unit for use in a library apparatus which stores a large number of cartridges such as magnetic tape cartridges and optical disk cartridges. The recording/reproduction unit performs processing such as writing/reading of recording/recorded data on/from a storage medium accommodated in the cartridge transferred through a transferring mechanism and inserted thereinto. The present invention more particularly relates to a cartridge insertion/discharge opening structure of the recording/reproduction unit.
2) Description of the Related Art
In general, a library apparatus functions as a large-capacity external storage memory, and a storage rack in its locker stores several thousands of cartridges each accommodating, for example, a magnetic tape as a storage medium, and access such as writing/reading of recording/recorded data is automatically performed on the storage medium within each of the cartridges.
Furthermore, in addition to the aforesaid storage rack (storage unit) for storing cartridges, the library apparatus is equipped with a station for conducting the entry of a cartridge from the external into the apparatus and the exit of the cartridge from the interior of the apparatus to the external, a plurality of magnetic tape decks (recording/reproduction units; which will be referred hereinafter to as decks) for conducting access such as writing/reading of recording/recorded data with respect to a storage medium (magnetic tape) within a cartridge, and an accessor robot (transferring mechanism; which will be referred hereinafter as an accessor) for performing the conveyance of the cartridges among the cartridge entry/exit station, the storage rack and the decks.
In such a library apparatus, in response to an access request to one cartridge from a host unit or the like, the accessor travels toward the storage rack to search for the cartridge there, and subsequently, a hand mechanism grips that cartridge and transfers it to the deck for insertion into the deck. With these operations, in that deck, given processing is done with respect to the storage medium (magnetic tape) within the inserted cartridge. After the completion of the processing, the cartridge discharged or ejected from the deck is again gripped by the hand mechanism and conveyed by the accessor up to the storage rack to be stored at a given position.
In a prior library apparatus, a dedicated cartridge delivering and receiving mechanism is installed in each of the decks so that the insertion of the cartridge into the deck or the extraction (pulling-out) of the cartridge from the deck is carried out through the cartridge delivering and receiving mechanism. In this case, the accessor is not designed to directly carry out the insertion/extraction of the cartridge into/from the deck.
In the case that the cartridge delivering and receiving mechanism is provided at every deck, the mounting space enlarges within the library apparatus and the system becomes complex complication. For this reason, the reduction of the mounting space and simplification of the system are desirable.
For meeting this requirement, an idea may naturally be born to omit the cartridge delivering and receiving mechanism and enable the accessor to directly carry out the insertion/extraction of the cartridge into/from the deck without the intervention of the cartridge delivering and receiving mechanism.
In a prior art, cartridge delivering and receiving mechanism intervenes between the accessor and the deck, and an insertion/discharge opening of the cartridge delivering and receiving mechanism is designed to be openable and movable, and therefore, even if the difference in position somewhat occurs between the accessor (the cartridge gripped by a hand mechanism) and the cartridge delivering and receiving mechanism, the accessor would be capable of certainly carrying out the insertion/extraction of the cartridge with respect to the deck owing to the intervention of the cartridge delivering and receiving mechanism.
On the other hand, in the case where the accessor directly performs the insertion/extraction of the cartridge with respect to the deck without the use of the cartridge delivering and receiving mechanism as mentioned above, if the accessor is misaligned with the deck, the insertion/extraction of the cartridge can be prevented.
This means that it is essential that the accessor be allowed to directly accomplish the insertion/extraction of the cartridge with respect to the deck regardless of the occurrence of the positional difference to some extent between the accessor and the deck. For this purpose, one possible way may be that a guide member is provided in an insertion/discharge opening section of the deck to guide the cartridge, inserted by the accessor toward the interior of the deck.
In this case, since several decks treat several thousands of cartridges in one library apparatus, the guide member of the deck opening section directly comes into contact with the cartridges at a considerably high frequency. Therefore, it is necessary that the guide member to be made of a material having not only superior strength and abrasion resistance but also a low contact resistance with respect to the cartridge so that the cartridge is always surely guided by the guide member.